Starting system for load-connected internal-combustion engines



Jan. 11, 1955 Filed June 15, 1950 F. F. STARTING SYSTEM FOR LOADCONNECTED INTERNAL-COMBUSTION ENGINES MURRAY 2,699,159

2 Sheets-Sheet 1.

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Jan. 11, 1955 F. F. MURRAY 2,699,159

STARTING SYSTEM FOR LOAD CONNECTED INTERNAL COMBUSTION ENGINES FiledJune 15, 1950 2 Shee-ts-Sheet 2 INVENTOR g /w 4am, 76

United States Patent STARTING SYSTEM FOR LOAD-CONNECTEDINTERNAL-COMBUSTION ENGINES Frederick F. Murray, Dallas, Tex.

Application June 15, 1950, Serial No. 168,334

Claims. (Cl. 123-182) This invention relates to a starting system forloadconnected internal combustion engine. More particular- 1y, itrelates to a system wherein an internal combustion engine assembly canbe started while connected to or under a large load without requiringthe usual interposition of mechanical or electrical clutch devices.

At the present time there is no practical system in use whereby internalcombustion engines, such as Diesel engines, can be permanently connectedto their respective loads because of the problem presented in startingsuch engines. As a consequence, such internal combustion engines arepresently provided with means for disconnecting the engines from theirrespective loads during the time that the engines in question are beingstarted. As they become power producers the loads are usually graduallyconnected until full driving connection is established between theengines and the loads.

A common means for connecting and disconnecting an internal combustionengine and its load may take one of the innumerable forms of frictionclutch devices. Normally, such clutches are used where the load isrelatively light. Where, however, the load to be carried or moved isrelatively large or heavy, resort may be had to an electrical clutchdevice such as those used in some diesel locomotives. This electricalclutch device may comprise an electric generator and electric motors sothat when the diesel engines of the locomotives are started, they turnthe generator under substantially no load until operating speed of thegenerator is attained. At that point the load is applied graduallythrough the electric circuits connecting the generator and motors. Theelectric motors in turn are mechanically and permanently connected tothe driving wheels of the locomotive. Not only is such an electricclutch device extremely expensive in that the internal combustionengines must be supplemented by the electric generators and electricmotors of correlated capacity but in addition the added control circuitsand mechanisms increase the expense and complexity of the operation.

In the case of hoisting machinery, the problem of internal combustionpower application and transmission during a starting phase follows thesame general pattern. That is to say that where the loads are relativelylight, mechanical means such as friction clutches are used with resortto the above described electrical clutch means when the leads to bestarted are relatively great.

In the present invention the foregoing difficulties are overcome andinternal combustion engines can be effectively and efiiciently usedwhile substantially constantly under or subject to load, even thoughthat load be relatively heavy or requires a high torque to move it.Further, by means of the system of this invention, such internalcombustion engines can be started without the interposition of anyclutch device, whether mechanical, electrical, or of other nature. Inbrief, in the provided system of this invention a compressor for thestarting and combustion air is in a new cooperative relation to operatethe internal combustion engine in question. This compressor is drivenwholly independently of the engine and hence is capable of making suchair available at a pressure and at a temperature called for in thedesign of the engine for the eflicient operation thereof. It is part ofmy system to use this air under pressure to start the engine and toignite fuel introduced directly into the engine whereby combustion isprovided within the engine cylinders to operate them and move the loadfirmly connected thereto either directly or 2,699,159 Patented Jan. 11,1955 through positively connected power transmission devices such asgears. 'lhus, by the system of this invention conventional items ofequipment are used and interconnected to produce an internal combustionengine assembly which can remain in relatively permanent connection toits load and, at the same time, be stopped and restarted withoutrequiring any complete or partial disconnection between that engine andthat load.

Other objects and advantages will be apparent from the followingdescription and from the drawings, which are schematic only, in which,

Figure l is a diagrammatic view of a hoisting machinery assemblyemploying the system of this invention with a two-cylinder, two-cyclediesel engine;

Figure 2 18 a view in schematic cross section taken through the axis ofone of the cylinders of the diesel engine shown in Figure l and normalto the crankshaft thereof, with air admission to said cylinder beginningto start the engine;

Figure 3 is a view similar to the view shown in Figure 2 with fuelinjection and combustion taking place;

Figure 4 is a view similar to the view shown in Figure 2 with the pistonsubstantially at the end of its outward or power stroke with exhausttaking place;

Figure 5 is a view similar to the view shown in Figure 2 WlIll thepiston on its inward or extended stroke with auxiliary exhaust takingplace;

Figure 6 is an enlarged end view in partial section of the engine shownin Figure 1 illustrating a means for ad- VfiflCll'lg and retarding theopening of the air admission va ve;

Figure 7 is a view corresponding to the view shown in Figure 2 showingadvance air admission after the engine is running, having been startedas shown by the sequence in Figures 2 to 5 inclusive; and

Figure 7A is a schematic view of a diesel locomotive employing thesystem of this invention.

in the assembly shown in Figure l, a derrick-type structural hoistingrig 10 is provided with a crown pulley 11 and a cable drum 12 pivotallymounted thereon. A flexible cable 13 is engaged by the drum at one endand anchored at its other end 14 after passing around pulley 11 and ablock sheave 15. A hook 16 is connected to block 15 and supports a load17 to be raised or lowered by the counterclockwise or clockwise movementrespectively of drum 12. When drum 12 is at rest a brake drum 18 fixedto the shaft of drum 12 may be engaged by a suitable brake block (notshown) to insure the holding of sheave 15 in whatever rest position isdesired whether load 17 is suspended or otherwise.

A sprocket wheel 19 is also fastened to the shaft of drum 12 and isengaged by a sprocket chain 20. Sprocket chain 20 also engages a drivesprocket 21 keyed to the end of a crankshaft 22. Crankshaft 22 is a partof a twocylinder, two-cycle diesel engine 23 and is suitably mounted onbearings within a crankcase 24. A flywheel 25 is provided at the otherend of shaft 22. It will thus be seen that engine 23 is permanentlyconnected to load 17 without any interposition of a friction clutch orany other form of mechanical, electrical or other clutching deviceintended to disconnect the engine and the load before starting theengine. Engine 23 is wholly conventional except that no provision ismade in connection therewith for taking air into the cylinders thereofin the course of any of the return or inward strokes in order to havethe engine compress that air for use as combustion air.

Engine 23 includes a cylinder block 26 bolted to crankcase 24 and acylinder head 27 in turn bolted to block 26. A high pressure airmanifold 28 which is preferably suitably lagged is connected to enginehead 27 and communicates with the interior of each cylinder of engine 23through suitable air admission valve means. The other end of duct 28 isconnected to the delivery end of an air compressor 29 which, as shown,is a reciprocating compressor although a centrifugal compressor may alsobe used. A relatively small receiver insulated to maintain temperaturemay be interposed between reciprocating compressor 29 and manifold 28.In general, such a receiver is not necessary particularly if acentrifugal compressor is used.

An air admission valve 30 is positioned in each duct 28a connecting acylinder with manifold 28. A valve 29a may be used to shut compressor 29off from engine 23 when engine 23 is to be brought to a stop. Acombination pulley flywheel 31 is keyed to a crankshaft 32 of compressor29 and is driven by V-belts 33 engaging the grooves in wheel 31 andcorresponding grooves in a driving pulley 34 directly connected to thearmature shaft of an electric motor 35. Instead of electric motor 35, agasoline motor or other prime mover wholly independent of engine 23 maybe used.

Crankshaft 22 is provided with two throws 36 angularly separated by 180inasmuch as engine 23 is illustratively described as a two-cylinderengine. Similarly, each cylinder operates through the identical cycle asthe companion cylinder by 180 angular degrees removed. In the cylindershown in Figures 2, and 7, a connecting rod 37 connects crankshaft 22with a wrist pin 38 which in turn is connected to a piston 39 providedwith the usual rings (not shown) for sliding engagement with the walls40 of each cylinder 41. Each cylinder is connected to an annular exhaustmanifold 42 communicating with the interior of the cylinder throughports 43 located adjacent that portion of walls 40 uncovered as piston39 approached the end of its working or outward stroke as shown inFigure 4. Inasmuch as engine 23 is a twocycle engine, it is apparentthat exhaust begins during the latter part of the outward or workingstrokes when the pistons 39 uncover the respective ports 43. Suchexhaust continues after the piston reaches retracted dead center asshown in Figure 4 and commences its return or inward stroke. After theports 43 of the respective cylinder are closed off by the piston 39,exhaust still continues through an auxiliary exhaust valve 45 in theform of a poppet valve in cylinder head 27. The valves 45 control theopenings in the respective cylinders into the auxiliary exhaust ports44. Normally, such ports 44 will be closed prior to the admission of airfrom the respective ports 28a although high pressure air may be admittedthrough the ports 28a into the respective cylinders to scavenge thosecylinders prior to the final closing of the valves 45. Such finalclosing normally will be caused to occur by conventional controls beforethe pistons 39 begin their respective outward strokes and will occurbefore completion of the introduction of air through the respectivevalves 30. In some cases such an auxiliary exhausting of the gaseousproducts of combustion through port 44 may be eliminated provided if,for example, ports 43 are 7 moved nearer to cylinder head 27 and valvedto avoid premature exhaust on the outward stroke.

As shown in Figures 2 to 7, air inlet valve 30 in the form of a poppetvalve or other suitable form is provided in cylinder head 27. Eachpoppet valve 30 is conventionally actuated by a cam 47 on a camshaft 48shown in Figure 6. Camshaft 48 is turned by a sprocket chain 49 whichalso engages a driving sprocket wheel 50 connected in a conventional wayto crankshaft 22 in synchronism therewith. A tensioning arm 51 having anidler sprocket wheel 52 rotatably fastened thereto is held in tensioningposition by a spring 53. Th other end of arm 51 is pivotally connectedto cylinder block 26 of engine 23.

A pair of rocking brackets 54 rotatably support the ends of camshaft 48for movement through an arc about the rocking centers 55 of the brackets54, said brackets being pivotally mounted on fixed lugs 54a on cylinderhead 27. A connecting bar 56 joins the other ends of the bracket 54 andis pivotally fastened to a link 57. Link 57 in turn is pivoted at itslower end to a movable lever 58 rotatably mounted about its axis 59 to alug 60 extending outwardly from cylinder block 26. A fixed quadrant 61has its arcuate surface indented for engagement by a movable dog 62 onlever 58 to hold camshaft 48 at any desired preset height above theupper end of the stems of the valves 30. It is evident that as lever 58is swung downwardly, camshaft 48 will be raised, delaying the time whencam 47 starts to open the respective valves 30, thereby retarding theadmission of starting and combustion air through air admission valves30.

At the starting of engine 23, air from compressor 29 can only beadmitted to whichever cylinder has its piston 39 just past its extendeddead-center position, as shown in Figure 2, in order to insureadequately high starting torque for such starting in the desireddirection of rotation which it is to have when it itself begins to runas a power producer. When engine 23 itself is running as a powerproducer, lever 58 may be raised the desired amount to lower camshaft 48and provide thereby for initiating air admission to the cylinders 41respectively somewhat in advance of extended or top dead-center.Further, the cams 47 may each be made of angularly rotatable portionsWhich can be bolted together or otherwise adjusted to change the lengthof the peripheral cam face and thereby change the duration of the airadmission period to the respective cylinders 41.

Fuel is injected into each cylinder 41 through a conventional fuelinjection nozzle 63 extending through wall 40 as shown within theclearance space in cylinder 41 substantially at the beginning of theoutward stroke. A conventional nozzle regulating valve 64 is connectedto nozzle 63 between it and a duct 65 through which fuel, usually in theform of a liquid, is fed. This fuel, which may also be in the form of apulverized solid, or in some cases of a very high pressure gaseous fluidunder a pressure higher than the pressure which it will encounter withincylinder 41 during the period of its introduction thereinto. Suchinjection of the fuel is preferably caused to occur by standard timingdevices (not shown) so as to follow air admission initiation and overlapat least the end of the air admission period. So introduced, the fueland air commingle, burn and force piston 39 into a power or workingstroke, as shown in Figure 3, with valves 30 and 45 closed.

The burning of the air-fuel mixture so introduced into each cylinder 41is brought about in the embodiment shown by having compressor 29 deliverits starting and combustion air through valve 30 at such pressure thatits corresponding temperature is sufficient to ignite the fuelindependently injected through the respective nozzle 63. On the otherhand, standard ignition devices, such as spark plugs, may be provided inthe cylinder head or wall adjacent the head and timed to spark bywell-known means to ignite the combustible mixture of air and fuelintroduced into the cylinders 41 substantially upon completion of theinward stroke of the pistons 39 therein. At first upon admission of airfrom compressor 29 and immediately thereafter during the burning of theair and fuel mixture causing the gaseous expansion to move each piston39 as shown in Figure 3, crankshaft 22 is turned in the desireddirection and moves the load to which it is connected, slowly at firstand with increasing rapidity until the frequency of the working or powerstrokes of the cylinders 41 based upon the design factors of the engine23 are such as to change engine 23 over from its starting phase asitself a load into its engine phase as a running power producer. Whenrunning, engine 23 continues to receive its combustion air undersufiicient pressure and temperature from compressor 29, the admissionthereof being suitably regulated as to initiation and duration by therespective valves 30. Under such circumstances, the return or inwardstroke of the cylinder pistons in engine 23 is not a compression strokein any sense of that term in the internal combustion engine art.

Instead, by the system of this invention, when each piston 39 reachesits top or extended dead-center substantially as shown in Figure 2 itthere defines the minimum cylinder clearance space under the relativelylow pressure of the exhaust step. Into that space starting andcombustion air under high pressure is admitted through valve 30. Hence,engine 23 itself has no compression of air to perform on its inwardstrokes allowing the full power application of its power strokes to beconverted into useful work on its load. Such increases the efficiency ofthe system of this invention and partly at least offsets the expense ofproviding the air compressor means 29. In selecting compressor 29 itwill be preferable not only to correlate it with the internal combustionengine with which it is to be used but also to provide a type of aircompressor which will have sufficient flexibility to afford desiredchanges in air pressure, volume and/or temperature. In this way, theequipment under this system can be used to provide a greater range ofperformance for varying conditions than would otherwise be the case ifthe performance were solely limited by the rating of the internalcombustion engine used. It is evident that the system of this inventionis wholly different in concept and operation from any conventionalsupercharging that is sometimes used with internal combustion engines.

As described above, the appropriate selection of one of the many formsof conventional air compressors will provide starting and combustion airfor use in the system of this invention at the predetermined volume,pressure and/ or temperature desired. Usually, these factors willcorrespond to the pressure and temperature of air which would beprovided if engine 23 in each were wholly conventional and were operatedin a conventional manner with air admitted thereto for compression onthe inward strokes.

The system of this invention is also fully applicable to the art ofmachines such as Diesel locomotives. In such a case, a combustion engineturbine or turbo-jet might be provided as the prime mover for a singleor twostage centrifugal compressor. would supply starting air atstarting or higher pressure and ignition temperature respectively to theDiesel engine cylinders on the locomotive substantially at the time ofminimum clearance dead-center whether the pistons in such cylinders aresingle or double-acting. In this way, the high pressure air would startto move the locomotive drivers. Then, as each piston in the engine movesor starts to move along its working or power stroke under the pressureof the air from the independent centrifugal compressor, fuel would beinjected into the cylinder and ignite because of the temperature of thatindependently supplied air to expand and increase the force on therespective piston or respective side of a double-acting piston. Suchfuel combustion substantially relieves, during the remainder of thepower or working stroke, the amount of output demanded of the compressorso that the compressor need only have enough capacity to initiatestarting movement of the pistons in the Diesel engine provided. Thismeans, of course, that the injection of the fuel begins to occur beforethe capacity of the compressor is exceeded at the time of starting. Forexample, a Diesel locomotive 66, partly shown in dot and dash outline inFigure 7A, may be provided with a conventional Diesel engine 23 directlycoupled by suitable gearing to the locomotive wheels. Starting andcombustion air may be supplied to the manifold of the engine 23' througha high pressure pipe 28 the other end of which is connected to theoutlet of a suitable conventional air compressor 29'. Compressor 29 maybe directly driven by a prime mover 35' which s shown may be anindependent internal combustion engine.

Thus, in the system of this invention starting and combustion air at apressure at least equal to the pressure which would be produced by thenormal compression ratio pressure of the engine used were that engine tooperate in a fully conventional manner with a conventional compressionstroke is supplied beginning substantially in the minimum clearancespace in the cylinders and preferably at least at fuel ignitiontemperature by wholly outside and independent means. The enginesconstructed for operation under the system of this invention thereforehave no need of any air intake or compression strokes but simply engagein expansion and exhaust strokes with the starting and other advantagesheretofore inachievable in any conventional engine assembly.

The selection of the relative weights, pressures and temperatures of airand fuel to be used in the system of this invention may be made by thoseskilled in the internal combustion engine art in accordance withexisting known relationships. Still further, in the system of thisinvention the initiation of the respective air and fuel introductionperiods and the respective durations thereof may be preset eachindependently of the other by the use of means currently available tothose same people who are skilled in this art. For example, the timingand quantity of fuel injection may be independently selected to continuefor a predetermined angular travel of the piston after it has reachedtop or extended dead-center dependent upon the torque or load-carryingrequirements of the particular assembly under construction. The valvetiming for the fuel injection nozzles as well as that for the airadmission valves can be accomplished by any of a number of valvegearmechanisms which are well established in the art of machine design.

Although the embodiment shown in the drawings is described in terms of atwo-cylinder, two-cycle Diesel engine, it will be evident that thesystem of this invention may be equally well applied to double-actingsinglecylinder internal combustion engines and to internal combustionengines having more than two cylinders. Moreover, in using either asingle cylinder or two-cylinder engine a standard mechanical jack tomove the engine This compressor in turn off dead-center may be providedfor use in the unlikely event that such engines should stop or beallowed to stop precisely on such dead-center. It can also be applied toengines operating on a four-cycle basis nor is this invention to belimited to particular nozzle, valving or porting details. For each rangeof desired output all of the engine factors and air compressor factorswill be correlated prior to the assembly in accordance with theknowledge of those skilled in the art in the light of the teaching ofthis invention. Thus, various modifications may be made which are withinthe spirit of this invention and the scope of the appended claims.

I claim:

1. In a system for starting an internal combustion engine under load,steps comprising, in combination, compressing a combustion supportingfluid by means of a prime mover driving a compressor independent of saidengine to apressure at least as high as that required to turn saidengine over, admitting said fluid under such pressure into thecombustion space of said engine when the position of extended deadcenter has been substantially attained, introducing fuel into said fluidand igniting the mixture of the same beginning at least by the time themaximum output capacity of said compressor is reached, and porting saidengine in the course of the return of the piston to said extended deadcenter to prevent material back pressure at least until said enginebecomes a power producer.

2. In a system for starting and operating an internal combustion engineunder load, steps comprising, in combination, compressing air by meansof a prime mover driving a compressor independent of said engine to apressure at least as high as that required to turn said engine over,admitting said air under such pressure into the combustion space of saidengine when the position of extended dead center has been substantiallyattained to turn said engine over, continuing said admission while saidengine is being accelerated suflicently to become a power producer,porting said engine in the course of the return of the piston to suchextended dead center position to provide a relatively low pressure insaid combustion space during said return, introducing fuel into said airbeginning at least by the time the maximum output capacity of saidcompressor is reached, igniting said air and fuel, and continuing theadmission of compressed air and fuel into said engine after said enginehas become such a power producer.

3. In combination, in a system for starting an internal combustionengine under load, apparatus comprising, a cylinder, a pistonreciprocable therein, a load-connected crank shaft turned by saidpiston, an air compressor for compressing air to a pressure at least ashigh as that re quired to move said piston, means independent of saidengine for driving said compressor, means for introducing compressed airfrom said compressor into said cylinder at about the time said pistonhas substantially attained its extended dead center position, means forexhausting said cylinder in the course of return of said pistonsubstantially until said means for introducing compressed air againintroduce said compressed air to maintain a relatively low pressure insaid cylinder substantially throughout said inward stroke, means forintroducing fuel into said cylinder for admixture with said compressedair beginning at least by the time the maximum output capacity of saidcompressor is reached, and means for igniting said mixture of compressedair and fuel.

4. In combination, in a system for starting an internal combustionengine under load, apparatus comprising, a cylinder, a pistonreciprocable therein, a load-connected crank shaft turned by saidpiston, an air compressor for compressing air to a pressure at least ashigh as that required to move said piston, means independent of saidengine for driving said compressor, means for introducing compressed airfrom said compressor into said cylinder when said piston hassubstantially attained is extended dead center position, means forexhausting said cylinder in the course of the return of said pistonsubstantially until said means for introducing compressed air againintroduce said compressed air to maintain a relatively low pressure insaid cylinder substantially throughout said inward stroke, means forintroducing fuel into said cylinder for admixture with said compressedair beginning at least by the time the maximum output capacity of saidcompressor is reached, and means for continuing to supply suchcompressed air to said cylinder after said engine becomes a powerproducer.

5. In combination, in a system for starting and operating aself-propelled land or marine vehicle, apparatus comprising, a powerproducing internal combustion engine to normally drive said vehicle, anindependent prime mover mounted in said vehicle, an air compressorconnected to said prime mover to compress air at least to a pressurehigh enough to turn said engine over to start said vehicle, means forcontinuing the admission of such compressed air to said engine at leastuntil the time the maximum output capacity of said compressor isreached, injecting fuel into said engine in timed relation to suchadmission of compressed air to form a combustible mixture, means forigniting said mixture of fuel and air, means for exhausting the productsof combustion from said engine, means for valving said engine to preventnormal compression stroke back pressure therein during nonworkingstrokes thereof at least until said engine becomes a power producer, andmeans for continuing to supply said compressed air to said engine afterit becomes such a power producer to supply at least a major portion ofthe combustion air required by said engine.

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